It is known in the art to provide spectrophotometers for measuring a color sample. For example, reference is made to commonly-owned U.S. Pat. App. Pub. No. 2008/0002204 (the “'204 Publication”), the contents of which are incorporated herein by reference for all permissible purposes. The '204 Publication discloses a color measurement device for use at various stages of industrial processes. The device of the '204 Publication offers enhanced insensitivity to ambient light, measurement depth variations, and/or ambient temperature variations. The device of the '204 Publication may be embodied as an LED-based color measurement spectrophotometer. In the device of the '204 Publication, over-illumination in full-spectrum of the target object facilitates effective color measurements over varying depths of view, and collected light is measured at discrete wavelengths across the entire visual spectrum. The hardened, rugged design and packaging of the measurement device of the '204 Publication allows color measurement to be performed at various stages of industrial processes, and the device can add value by enabling enhanced detection of color errors.
The device of the '204 Publication and other spectrophotometers can incorporate numerous advantageous features. For example, reference is made to commonly-owned U.S. Pat. No. 6,888,633, the contents of which are incorporated herein by reference for all permissible purposes. The device of the '204 Publication can include a synchronous modulation-demodulation scheme in connection with the illumination and collection optics. Spectrophotometers can incorporate such advantageous features as LED thermal stabilization, light-emitting diode (LED) illumination, amplification features, minimizing sensitivities to depth variation, and other features discussed in commonly-owned U.S. Pat. No. 7,262,853 and those divisional applications thereof (now commonly-owned U.S. Pat. Nos. 7,092,097 and 7,145,657), the contents of all of which are incorporated herein by reference for all permissible purposes.
Prior art point-of-purchase (POP) spectrophotometers for retail consumer use have typically included closed-viewing chambers for measuring a color sample. For example, as shown in FIGS. 1A and 1B of the present application, a prior art POP spectrophotometer is shown that might typically be used at a retail paint store for color matching. One hand of a user is typically required to pivot open a stop between an open and closed position, while, at the same time, another hand of the user is required to insert a planar color sample between the stop and internal optics. Moreover, the color sample typically comes in physical contact with components of the prior art POP spectrophotometer, thereby making it difficult to measure wet color samples. As also shown, the color sample is conventional, being formed of a piece of paper with color disposed thereon.
Retail and other consumers of architectural paint, for example, whether they be professional painter or merely an everyday do-it-yourselfer, have come to expect the ability to get instant and exact matches to any color sample they provide at the point-of-purchase—even if the color sample cannot fit in a conventional sample holder or has surface qualities that defeat the measurement geometries of traditional instrumentation. Custom paint formulation is now the common expectation rather than the differentiating exception.
What is needed in the art is a spectrophotometer with enhanced ease of use to overcome these and other disadvantages.